用vb编程如何实现用鼠标滚轮扩大和缩小窗体上图片？

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1、请教：用vb编程如何实现用鼠标滚轮扩大和缩小窗体上的图片？2012-09-2515:54提问者：caijigao22

2、浏览次数：68次提交回答满意回答2012-09-2517:44添加一个模块，输入以下代码：PublicDeclareFunctionCallWindowProcLib"user32"Alias"CallWindowProcA"(ByVallpPrevWndFuncAsLong,ByValhwndAsLong,ByValMsgAsLong,ByValwParamAsLong,ByVallParamAsLong)AsLongPublicDeclareFunctionGetW

3、indowLongLib"user32"Alias"GetWindowLongA"(ByValhwndAsLong,ByValnIndexAsLong)AsLongPublicDeclareFunctionSetWindowLongLib"user32"Alias"SetWindowLongA"(ByValhwndAsLong,ByValnIndexAsLong,ByValdwNewLongAsLong)AsLongPublicDeclareFunctionGetCursorPosLib"user32"(lpPointAsPOINTAPI)AsLongPublicDeclareFunc

4、tionWindowFromPointLib"user32"(ByValxPointAsLong,ByValyPointAsLong)AsLongPublicConstGWL_WNDPROC=-4&PublicConstWM_MOUSEWHEEL=&H20APublicTypePOINTAPIxAsLongyAsLongEndTypePublicOldWindowProcAsLongPublicohwndAsLongPublicFunctionNewWindowProc(ByValhwndAsLong,ByValMsgAsLong,ByValwParamAsLong,ByVallPar

5、amAsLong)AsLongOnErrorResumeNextIfMsg=WM_MOUSEWHEELThenDimCurPointAsPOINTAPI,hwndUnderCursorAsLongGetCursorPosCurPointhwndUnderCursor=WindowFromPoint(CurPoint.x,CurPoint.y)IfhwndUnderCursor=ohwndThenIfwParam=-7864320ThenIfForm1.Picture1.Width

6、e1.Width+300IfForm1.Picture1.Height600ThenForm1.Picture1.Width=Form1.Picture1.Width-300IfForm1.Picture1.Height>480ThenForm1.Picture1.Height=Form1.Picture1.Height-240EndIfEndIfElseN

7、ewWindowProc=CallWindowProc(OldWindowProc,hwnd,Msg,wParam,lParam)EndIfEndFunction在Form1中放入一个Picture1控件，然后输入以下代码：PrivateSubForm_Load()Picture1.AutoRedraw=TruePicture1.Picture=LoadPicture("e:tmpcd1.gif")'图片文件名，自己改Picture1.Move0,0,6000,4800ohwnd=Picture1.hwndOldWindowProc=GetWindowLong(Picture1.h

8、wnd,GWL_WNDPROC)CallSetWindowLong(Picture1.hwnd,GWL_WNDPROC,AddressOfNewWindowProc)EndSubPrivateSubPicture1_Resize()Picture1.PaintPicturePicture1.Picture,0,0,Picture1.ScaleWidth,Picture1.ScaleHeightEndSub